{"id":154,"date":"2013-12-31T22:21:55","date_gmt":"2013-12-31T14:21:55","guid":{"rendered":"http:\/\/powerquality.sg\/wordpress\/?p=154"},"modified":"2014-03-27T07:14:57","modified_gmt":"2014-03-26T23:14:57","slug":"230kv-voltage-dip-31122013-1905hrs","status":"publish","type":"post","link":"http:\/\/powerquality.sg\/wordpress\/?p=154","title":{"rendered":"230kV Voltage Dip – 31\/12\/2013 1905hrs"},"content":{"rendered":"

Another transmission level (230kV) fault happened earlier at 19:05 hrs.
\nPlaces in the Western area would have seen the worst dip magnitudes \/duration ( ~ 50% dip by)<\/p>\n

* Will update with a waveform from one of our PQ monitors in the West soon.<\/p>\n

Till then;\u00a0 Happy 2014 ! (in advance)<\/p>\n

Update: 2\/1\/2014<\/span><\/strong><\/p>\n

From the following waveforms, we can conclude that there was a 230kV single phase \u00a0fault on Phase L1 (red)<\/p>\n

Voltage Dip Waveform Captured In the West (22kV) – Dip by 40.83%, 78ms<\/p>\n

\"Voltage<\/a>
Voltage Dip Waveform 31-12-2013 1905hrs (at 22kV)<\/figcaption><\/figure>\n

Voltage Dip Waveform Captured In the West (Low Voltage-230V) – Dip by 43%, 80ms<\/p>\n

\"Voltage<\/a>
Voltage Dip Waveform 31-12-2013 1905hrs (at Low Voltage)<\/figcaption><\/figure>\n

 <\/p>\n

Notes:
\nA transmission level fault will cause an islandwide voltage dip.
\nHere, in Singapore. a voltage dip is defined as a drop of more than 10% of the nominal voltage (Line voltage). It typically lasts around 200ms.<\/p>\n

In Singapore, the transmission network consists of a 400kV network, overlayed onto 4 x 230kV blocks. The 230kV blocks were split up in the mid 2000s, for controlling of fault level.
\nIt has inherently brought an advantage: Minimize the impact of a voltage dip due to a 230kV transmission fault to just that particular block.<\/p>\n

Hence in a 230kV fault, only connected customers in that particular block which the fault occurred will \u2018see\u2019 severe dip values (usually in the ranges of 40-50% dip by magnitude for single phase 230kV faults); Customers in the lower voltage levels (66kV, 22kV…) of that block will see similar (as seen at 230kV) dip severity or less (slightly).<\/p>\n

The other 3 blocks will see significantly less severe voltage dip or just a slight variation of the nominal voltage.<\/p>\n","protected":false},"excerpt":{"rendered":"

Another transmission level (230kV) fault happened earlier at 19:05 hrs. Places in the Western area would have seen the worst dip magnitudes \/duration ( ~ 50% dip by) * Will update with a waveform from one of our PQ monitors in the West soon. Till then;\u00a0 Happy 2014 ! (in advance) Update: 2\/1\/2014 From the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_newsletter_tier_id":0,"jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false}}},"categories":[10],"tags":[],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p41TEZ-2u","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/154"}],"collection":[{"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=154"}],"version-history":[{"count":10,"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/154\/revisions"}],"predecessor-version":[{"id":157,"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/154\/revisions\/157"}],"wp:attachment":[{"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=154"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=154"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/powerquality.sg\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=154"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}